The present invention relates to the field of printed circuit boards. More particularly, this invention relates to a clip for securing a heat sink to a chip on a circuit board.
Several methods have been used to secure heat sinks to chips on circuit boards. Heat sinks may be attached to a chip by using epoxy. However, epoxy generally has handling problems which can make field use difficult.
Next, the heat sink may be attached to the chip using fasteners that attach to or pass through the circuit board. However, fastening the heat sink directly to the circuit board requires several large fastener holes. These holes may cause trace routing problems, particularly if the fastener holes are located directly between chips on the circuit board.
In addition, chips that are attached to the circuit board by sockets may have the heat sink attached to the socket. However, this is inapplicable if the chip is soldered directly to the printed circuit board.
What is needed is a heat sink attachment that reduces the openings in the printed circuit board without the use of epoxy and that also works for chips that are directly soldered to the printed circuit board.
One embodiment of the present invention provides a heat sink assembly for securing a heat sink to a chip on a circuit board using a clip to secure the heat sink to the chip. The assembly includes a pair of support beams, a clip attached to the pair of support beams, and a heat sink. Optionally, the assembly also includes a plurality of bias members biased between the heat sink and the circuit board and a pair of positioning pins positioned between the heat sink and the circuit board. The clip is biased between the heat sink and the pair of support beams.
One embodiment of the present invention includes a clip for attaching a heat sink to a circuit board. The clip has a plate having a first end and a second end with the first end having an aperture for fastening the first end to a first support beam and the second end having a hook for fastening the second end to a second support beam. Optionally, the clip is made of spring steel and provides a downward biasing force of between about 3 psi and about 25 psi and preferably about 10 psi.
One embodiment of the present invention includes a method of securing a heat sink to a chip on a circuit board. The method includes providing a clip and a pair of support beams, securing the clip to the support beams, and biasing the clip against the heat sink. Optionally the method may also include positioning the heat sink with a pair of positioning pins located between the heat sink and the circuit board.